The interviewing process varies from place to place and school to school. Below is a typical interview process for teachers.
In most areas, teachers generally have to pass several rounds of interviews before they are hired.
Stage 1: Expect a "screening interview," in which you will probably meet with an administrator (usually a school's principal).
Stage 2: If you pass the screening interview they will call you back to arrange a second interview. This time you'll meet with a large committee, which will include a school principal, a few teachers, and other members of the school staff. They will each take turns asking you specific questions.
Stage 3: If you've made it past the committee, they're going to call you back again. This time, they'll probably ask you to teach a sample lesson with a real class of students. (If you interview in the summer when school is out of session, you may get lucky enough to skip this step.)
Stage 4: If you are called back again, the next step is to meet with a higher-level administrator, such as a superintendent or assistant superintendent. If you reach this point in the interview process, this usually means the committee has recommended you as one of the top candidates and they want to present you as one of their preferred choices for the job.